1 files changed, 14 insertions, 12 deletions

diff --git a/chromium/v8/src/heap/safepoint.cc b/chromium/v8/src/heap/safepoint.cc
index e6ccf642c09..3012413f48c 100644
--- a/chromium/v8/src/heap/safepoint.cc
+++ b/chromium/v8/src/heap/safepoint.cc
@@ -13,13 +13,16 @@ namespace v8 {
 namespace internal {
 
 GlobalSafepoint::GlobalSafepoint(Heap* heap)
-    : heap_(heap), local_heaps_head_(nullptr), is_active_(false) {}
+    : heap_(heap), local_heaps_head_(nullptr), active_safepoint_scopes_(0) {}
 
-void GlobalSafepoint::Start() { StopThreads(); }
+void GlobalSafepoint::Start() { EnterSafepointScope(); }
 
-void GlobalSafepoint::End() { ResumeThreads(); }
+void GlobalSafepoint::End() { LeaveSafepointScope(); }
 
-void GlobalSafepoint::StopThreads() {
+void GlobalSafepoint::EnterSafepointScope() {
+  if (!FLAG_local_heaps) return;
+
+  if (++active_safepoint_scopes_ > 1) return;
   local_heaps_mutex_.Lock();
 
   barrier_.Arm();
@@ -37,12 +40,13 @@ void GlobalSafepoint::StopThreads() {
       current->state_change_.Wait(&current->state_mutex_);
     }
   }
-
-  is_active_ = true;
 }
 
-void GlobalSafepoint::ResumeThreads() {
-  is_active_ = false;
+void GlobalSafepoint::LeaveSafepointScope() {
+  if (!FLAG_local_heaps) return;
+
+  DCHECK_GT(active_safepoint_scopes_, 0);
+  if (--active_safepoint_scopes_ > 0) return;
 
   for (LocalHeap* current = local_heaps_head_; current;
        current = current->next_) {
@@ -90,12 +94,10 @@ void GlobalSafepoint::Barrier::Wait() {
 }
 
 SafepointScope::SafepointScope(Heap* heap) : safepoint_(heap->safepoint()) {
-  if (FLAG_local_heaps) safepoint_->StopThreads();
+  safepoint_->EnterSafepointScope();
 }
 
-SafepointScope::~SafepointScope() {
-  if (FLAG_local_heaps) safepoint_->ResumeThreads();
-}
+SafepointScope::~SafepointScope() { safepoint_->LeaveSafepointScope(); }
 
 void GlobalSafepoint::AddLocalHeap(LocalHeap* local_heap) {
   base::MutexGuard guard(&local_heaps_mutex_);